Dirhodium(II)-Catalyzed Intramolecular Carbon-Hydrogen Insertion Reaction of α-Diazoketones : Synthesis of 7-Silyloxyoctahydrobenzo[b]furan-2-ones

概要

論文の詳細を見る
A dirhodium(II)-catalyzed intramolecular C-H insertion reaction of 2-oxygen-substituted cyclohexyl diazoacetoacetates 1a-f was investigated. In contrast to the trans-2-methoxy- 1a and trans-2-(p-methoxybenzyloxy)-cyclohexyl derivatives 1b, which, upon treatment with 1 mol% dirhodium(II) tetraacetate in boiling benzene, gave a complex mixture, the trans-2-(tert-butyldimethylsilyoxy)cyclohexyl derivative 1c gave, in addition to the β-lactone 3c (16%), cis- and trans-fused octahydrobenzo[b]furan-2-ones 2c in 22 and 18% yields, respectively. Similar treatment of the cis-isomer 1d gave the β-lactone 3d as the major product (34%) and cis- and trans-fused γ-lactones 2d (7 and 18% yields, respectively) as minor products. The (1R^*, 2R^*, 3R^*)-3-benzyloxy-2-(tert-butyldimethylsilyloxy)cyclohexyl derivative 1e gave the γ-lactones 2e in 75% combined yield as a 5 : 2 mixture of cis- and trans-fused isomers, while the (1R^*, 2R^*, 3R^*)-isomer 1f afforded the trans-fused γ-lactone 2f in 62% yield as a single product.
公益社団法人日本薬学会の論文
1997-04-15